Replacing the Mustang II Bumpers
The Outer Structure
One of the first places to start when working on a Mustang II is typically the front and rear bumpers. The factory bumper covers were made out of a very flexible urethane, with a very thin metal backing. This meant that not only would the inside of the bumper (and bolts and hardware) rust and warp over time, but the urethane would also degrade. This causes the bumpers to sag, look "wavy" and suffer from cracking paint.
Additionally, there is a bumper trim strip that is part of the factory bumper assembly. This is a rubber strip that runs the length of the bumper and is secured inside of a channel. This is often one of the first things that people want to remove or "delete" to obtain a cleaner looking profile.
The Inner Structure
The structure on the inside of the bumper cover, called the crossmember, is meant to absorb the impact when in a collision. It is attached to 2 pistons that are meant to collapse when in a low speed impact. These can usually be retained if rust and/or time has not caused it to degrade too much. The crossmember is the link between the outer urethane shell and the impact absorbers. It bolts directly onto a plate that is welded to the "pistons" and, when unbolted, allows the whole bumper assembly to come free
What are the options for replacing the bumper?
A lot of people don't like the bulbous look of the mid 70's bumpers and are in search of a sleeker, more modern, profile. As such, there are a number of different bumpers available on the market:
- Factory Style - this is a direct replacement of the urethane bumper. It maintains the factory profile, but eliminates the sagging and need for a flexible paint
- Trim Delete - This style removes the channel for the bumper trim strip but still maintains the factory profile and dimensions. The crossmember can be retained and bolted up like factory.
- Full Tuck - Perhaps the most popular modification is the full tucked bumpers. The "full tuck" brings the entire depth of the front and rear bumper into the quarter panels and makes for a fully flush profile. The factory bumper ridges are kept, but the bumper will not protrude past the grill (front) or the hatch (rear).
- Mid Tuck - The mid-tuck bumpers are very similar to the OEM style, but is trimmed down about 2 inches. This means that it will look very similar to the factory car, but won't protrude from front and rear quite as much. It is a popular option for those in search of an OEM+ look.
- R Apron - The R apron bumper is based off the Shelby GT500 with a large opening for the radiator. It requires additional bracing to be utilized as the crossmember will not fit.
What about the Cobra or King Cobra?
Both the Cobra II and King Cobra both utilize the same factory bumper, the only difference being that there is a valance and spoiler (Cobra II) or full air dam (King Cobra) below the bumper. The factory bumpers still protrude past the air dam or spoiler, and are still meant to absorb a slow impact. It is important to note that all bumper options are compatible with either the Cobra II or King Cobra, except for the R Apron, which covers the whole of the front of the car.